[RFC 2/2] nvmet-rdma: Matching rdma WC to rdma queue according to WC QP

[Sagi Grimberg]

On 08/08/16 14:00, Roy Shterman wrote:
> Today when assiging rdma_nvme_queue to rdma work complition we use
> cq_context which is passed as queue pointer when creating the CQ.
> In case we will want to aggregate few QP to one CQ this method will
> not work, hence it will be better if we will use QP context instead.
>
> Signed-off-by: Roy Shterman <roysh at mellanox.com>
> ---
>  drivers/nvme/target/rdma.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
> index e06d504..164b1a2 100644
> --- a/drivers/nvme/target/rdma.c
> +++ b/drivers/nvme/target/rdma.c
> @@ -547,7 +547,7 @@ static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
>  {
>  	struct nvmet_rdma_rsp *rsp =
>  		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, read_cqe);
> -	struct nvmet_rdma_queue *queue = cq->cq_context;
> +	struct nvmet_rdma_queue *queue = wc->qp->qp_context;
>
>  	WARN_ON(rsp->n_rdma <= 0);
>  	atomic_add(rsp->n_rdma, &queue->sq_wr_avail);
> @@ -726,7 +726,7 @@ static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
>  {
>  	struct nvmet_rdma_cmd *cmd =
>  		container_of(wc->wr_cqe, struct nvmet_rdma_cmd, cqe);
> -	struct nvmet_rdma_queue *queue = cq->cq_context;
> +	struct nvmet_rdma_queue *queue = wc->qp->qp_context;
>  	struct nvmet_rdma_rsp *rsp;
>
>  	if (unlikely(wc->status != IB_WC_SUCCESS)) {
>

Christoph and I had some discussions over that in the past. We came to
the conclusion that a RDMA core API for per-cpu CQ pools might be
beneficial for other target mode drivers (isert, srpt).

I even had an RFC in the works, but it kinda got left behind... It'd be
great if you can take it from there...